1. Field of the Invention
The present invention relates to locking means and more particularly to electronic locking means.
2. Description of the Prior Art
Electronic locking means are known in the art in which there is an interaction between the key part and the lock part.
Specifically, a device for identifying information allocated to a first carrier component (key part) with the assistance of read means which are disposed at a second carrier component (lock part) is known from the German OS 26 57 182. In that patent, a device is disclosed in which the information is contained encoded in a first information carrier in said first carrier component and the first carrier component also exhibits a reception element and a signal generator influenceable by the first information carrier. The second carrier component likewise exhibits a reception element as well as an evaluation circuit containing a second information carrier. The second carrier component is connected to an energy source which can be placed in an energetic coupling with the reception element of the first carrier component for the purpose of transmitting the energy for activating the components of the first carrier component and for driving the first information carrier.
By this means, the signal generator emits an information signal impressed by the information of the first information carrier which is received by the reception element in the second carrier component and, if need be after conversion, is compared in the evaluation circuit to the reference information of the second information carrier, and whereby the evaluation circuit emits a characteristic output signal when first and second information have a desired relationship to one another.
Significant features of the above device are, among other things that an energy evaluation stage is allocated to the reception element in the first carrier component, that energy evaluation stage only initiating a drive of the first information carrier when the received energy exceeds a minimum value; complementary parts of an electronic signal generator are provided in the first and second carrier components; the electronic components of the first carrier component are a frequency and/or amplitude determining circuit part of the signal generator; the first carrier component contains an oscillator at whose input an impedance coil lies and the second carrier component exhibits a second impedance which can be coupled to the first impedance; and the impedance coils contain ferrites designed as ferrite antennas.
Given this known identification means realized in a lock/key combination, the following problems remain unresolved between the lock and key, namely that a signal impression at the key side must be recognized at the lock side; the signal impression at the key side must ensue at precisely predetermined points in time so that the lock side can concentrate only on these points in time and the lock side is synchronized in the signal recognition to the points in time at which the signals appear; and an encoded signal impression must ensue at the key side.